


Scientific Experiment

by Luisssaugust



Category: BNA: Brand New Animal (Anime)
Genre: Anal Sex, Bottom Shirou, M/M, Oral Sex, Top Alan, a lot of smut, blowjob
Language: English
Status: Completed
Published: 2020-07-18
Updated: 2020-07-18
Packaged: 2021-03-05 02:40:25
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Graphic Depictions Of Violence
Chapters: 1
Words: 3,790
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25366987
Author URL: https://archiveofourown.org/users/Luisssaugust/pseuds/Luisssaugust
Summary: Ogami Shirou was living his life as always, being the White Wolf and taking care of Anima City. However, after receiving a message from Kagemori Michiru, his new friend, and be invited to the Sylvasta Laboratory to see some kind of new experiment. He ended up being trapped by Alan Sylvasta, who plan to do a strange and questionable experiment with the beastman.
Relationships: Alan Sylvasta/ Ogami Shirou
Comments: 7
Kudos: 72





	Scientific Experiment

Earlier in the morning, Shirou was patrolling the city as always, until he receives a message from Kagemori, saying she needed to talk to him in the Sylvasta Laboratory as quick as possible, that it has to do with the recent cases of beastmen going wild. That was weird, he was sure that the girl was having a date with her best friend, the Nazuna girl. However, if is about the events that put Anima City in danger he had to do something.

He ran as faster as he could, using his power as Silver Wolf to cross the entire city in less than twenty minutes. When he arrived at the Sylvasta’s Lab, he took a good look at that building and growled a little, he never liked that place. Allowing humans to build that thing in the middle of the place that supposed to be the paradise of Beastmen, that was wrong. The one thing that he liked even less than the company, was the man who was in charge of everything, Alan Sylvasta. That pretentious boy, who thinks he can rule the city. Shirou couldn’t wait to see that scum leaving Anima City.

For the first time in a long time, he entered through the front entrance, without trying to sneak in as usual. Once inside the building the stench of human beings invaded the beastman’s nostrils. He just wanted to find Michiru, discover what was happening and then go home.

He texted many times the girl, but without any response, eventually he had to ask/intimidate a lab worker about where he could find her, the person said that she was waiting in the main laboratory, way down in the building. He walked all the way down, having to “gently coerce” some guys to tell him where was the main lab. When he arrived he had a not very good reception.

Alan Sylvasta was the one who received Shirou, a young blond richman, with terrible personality. The last person that the wolfman would like to see, but he was not surprise, after all that man was the owner of the place. Shirou dispensed greetings.

— Where is Kagemori? What is so important that she would make me come to this human nest.

— So direct to the point. Calm down a little Mr. Shirou. Mrs. Kagemori is helping me with my new experiment. — Alan said.

— What? What did you say?! — Shirou cut the distance between him and the Sylvasta guy with one quick jump and grabbed his tie, the gray haired man was clearly upset. He would not allow beastmen become guinea pigs in the hands of humans. Alan was smiling.

— She is fine. Please, she told me that she wants to help with this particular experiment. It can help to solve the problems with wild beastmen. — Shirou released the youngman’s tie, but continued his aversion to all that.

— I don’t believe in you. Show me where is Michiru and I will trust in what she will say about the things you are doing. — Alan released a little sigh of displeasure and then got back to his normal smirk.

— Very well. If you insist so much. Please, accompany me to next room. The girl is in the middle of an exam, but she will definitely be glad to see the face of a friend. — Alan led the way to a door at the end of the main laboratory.

Shirou had noticed something, at the beginning when he arrived in the main lab, there were some people working here and there, but one by one, they start to leave, now that was only three or four people still around, but even they start to get their stuff while both Alan and Shirou were getting closer to the room. “What was he planning to do?... Ha! It doesn’t matter” that was the beastman thought, “I just need to get Michiru back and punch everyone until we leave this horrible place”.

Alan was the first one to enter the room, followed by Shirou, it was really dark, but the wolfman could sense Michiru’s smell there. He went even deep inside of that darkness, guided by his senses.

— Michiru, I am here! Michiru? — The lights suddenly turned on. The room was empty, except for a sports jacket that he immediately recognized that it belonged to his friend, the only people inside that white box were Shirou and Sylvasta. — What’s going on here? Where is Michiru? Answer me, your brat!

Then something happen, the wolfman became to feel dizzy and sleepy. In less than a minute he was on the knee, incapable of standing up.

— What did you do with me? — Shirou demanded to know.

— Nothing! Just a little bit of tranquilizer gas. — Alan smirk became even bigger than before, it was almost like he suddenly had acquired fangs.

— Impossible! A gas would not be enough to stop me…I am…am…Silver… — The poor beastman couldn’t finish his words.

— Maybe normal gas can’t work with you, however, this one were especially developed to deal with your inferior type. — Alan approached the unconscious body of that wolf. When really close, he moved a lock of hair, to have a better look of his prey and new specimen. — What a shame. If you were a pure blood you would never fell for that little trick. Well, anyway it’s time to you and me have some fun together.

Shirou woke up in the same room that before, but the situation now was completely different. First of all, he was fully naked, with a collar in his neck and also chained by strong steel chains that held him close to the ground, he couldn’t move his arms.

The second thing he noticed was Alan Sylvasta sitting on a chair in front of him. The man was more stripped, now he wasn’t wearing his tie, coat and waistcoat. Shirou was extremely ashamed of being in such place, trapped and naked in front of that hideous human. The wolfman tried the best to covered his parts with the legs.

— Eh… You don’t need to hide yourself from me little puppy. I promise that will not make you any harm, if you behave well. — Alan said. The gray haired man didn’t believe in anything that he said, who is he calling “Puppy”.

— What did you do with Michiru? — Shirou yelled to the youngest.

— Me? Nothing. She is probably still on her date with Nazuna, as the cameras on the city shows.

— WHAT? So…how? — The Sylvasta smilled.

— How did I bring you here? It was just a matter of hacking into your phone and pretend to be Michiru. And you fell like a dumb kid. — Shirou was so angry, he could kill that guy if he wasn’t chained. — Anyway, forget the girl a little, there are things more interesting to pay attention and I’m looking for one right now.

Alan was focused on Shirou, who in response growl to the rich boy. When Shirou instead of relaxing continued in a defense position, hiding his lower front, Alan got up from the chair and walk to get closer to him.

— The little puppy still doesn’t believe in me. Fine, I think I need to teach some good manners to my new pet. — With a single movement, fast and strong, the young man kicked Shirou, making him go full to the ground, full exposed to the next movement.

Alan took position on top of the beastman, dominating him, holding his hands tightly and giving no chance to Shirou reverse the situation. Shirou couldn’t believe how strong Alan was, he was just a man, a rich, stupid and weak human being, how could someone like him overcome a beastman, worst, how could he be overcoming the Silver Wolf.

— Now, how about we start to play for real. — Alan held both of Shirou’s hands with just one of his, the other hand he moved further down to meet with Shirou’s still soft rod. With a strong grab he started to masturbate the wolfman. At first the movements were forceful and intimidating, but after a couple minutes were noticeable the presence of some ability there. The wolf couldn’t resist, his member become hard as a rock and he was feeling good and ashamed at the same time.

— Oh, you are already hard. That was pretty easy, puppy. — He was messing with him. Some more stimulation in his staff and the things would be in his full control. Alan decided to play with the balls of that man. Again, with a strong grab, that made Shirou moan at loud. Despite the wolfman’s efforts to hide his emotions from that arrogant man, he couldn’t deny that he was feeling amazing. How long have being since the last time someone touch him that way. In some point he had to bite his lips to contain some moans.

—Why are you doing this to me? — Shirou questioned.

— I want to see how strong and different your type is from the others… from the pure blood, and to do that I need to make some experiments.

— I don’t know what you are talking about. Let me go, right now. — Alan masturbated him more, just to see his face squirm with pleasure. — Ahhh! You bastard!

The young Sylvasta was aware of Shirou’s condition, one last movement and he would not resist anymore. Alan left the balls and then with a simple and direct move goes to the entrance of Shirou’s ass. Already putting two fingers and starting to play with his inside.

Shirou could not hold his moans any longer. He left a groan so loud, that echoed through the entire room and would definitely be heard from the outside, if the room wasn’t sound proof. Alan was the one who was having more fun, he kept stroking his fingers deep down into Shirou, sometimes making them apart to expand the entrance, and as a reward he could hear the sweet moans of his naughty puppy. The last thing he did was added a third finger and stroking the fastest as he could into that ass. Shirou was losing his mind and ended up cumming, his sperm falling all over himself.

Shirou’s mind was blank, he didn’t understand what was happening. He didn’t remember when was the last time he came so much and so fast. His arms and legs were tired and he just want to rest in the floor, naked and covered in his on cum. When he opened his eyes he came across with Alan’s cock right in front of his face.

That was too much, that thing was to big, bigger than Shirou own penis. It was just centimeters away from his face and the smell was so strong, it was making him crazy.

— Come on. Don’t be shy. I know that you want. — Alan start to rubbing his fat rod against Shirou, hitting his cheeks and though the lips. The scent that came from that shaft was taking over of him. He just opened his mouth a little, his tongue just wanted to taste a bit of that behemoth in front of him, but he still resisted, he would not give in so easy.

When Shirou didn’t cooperate, the pretentious blond boy had to take the control again. He grabs the beastman’s face, make him open as much as possible and when he got a good look of the wolf’s mouth, he shoved his cock deep inside, leaving in there for a long time, to the point of making Shirou choke with all of that.

— Ahhh! Your mouth is even better than I thought! — Alan said, enjoying the sensation of having his mighty wood being sucked so well by that man. The feeling was so good as if he was melting there. He took away most of what was inside, lefting just the tip of his cock, he wanted to see Shirou’s expression a little before the next part.

Looking to that man, who was supposedly to be the protector of all Anima City, with such a passive expression, eyes sparkling, enjoying while sucking him, that was strangely the cutest and soft thing that the Sylvasta had saw in his entire life. Alan felt his face get warm up and become aware that he was blushing. The young rich boy couldn’t resist the wolfman, he wanted him, all of him. He was going to take it.

Alan pulled by the hair Shirou’s head, trying to positioning the best possible with his penis. One last look into that calm and seductive expression of the wolf, before he smashes all his cock inside the cute mouth, going deep until hit the throat. He continued to do a series of strokes, each one hitting that chin and sending vibrations to the whole body of the gray puppy. Shirou barely could breath, but he also wasn’t complaining.

The wolfman just accepted the situation, after the first time that the Sylvasta’s rod got inside and he tasted the pre-cum and smelled that powerful scent, he knew that he had lost. Right now, he was just enjoying while his throat was being obliterated. However, he would not be just a submissive scared puppy. That was also a fight, even if he didn’t win, he still would fight.

— AAAAHHHHH! — Alan screamed. — Your stupid bitch. — He took away his cock from Shirou’s mouth, just to see a mark of a bite. Now Shirou was the one smirking.

— So, that’s how we are going to play, huh? — at first the rich boy looked really angry, but then he smiled like a beast. — Very well, I will fuck you the whole night, until you can’t even stand up.

— Try your best your pretentious little brat!

Alan jumped in top of Shirou and turn him until he be face down to the floor, his buttocks up. Alan didn’t lose time and used his tongue to lick the entrance of that butt and go inside. All the action that was happening there was making Shirou go crazy, he could felt that tongue going deeper and deeper, almost touching the further point of his ass. That continued for at least fifteen minutes. Alan was really enjoying the flavor, but he wanted more than that, his cock wouldn’t wait anymore.

He turned Shirou again, now both of them were face-to-face. Shirou’s face was a mess, he had clearly drooled a little and was completely red. Alan also had the face completely red, the strangest part was that both were seemingly happy.

— I want to see your pathetic face cry when I begin to fuck you. — Alan said.

— You talk too much. Prove with actions, not words, you boring brat.

Shirou’s hole was well stretched because of the previous action, so there was no resistance when that fat head kissed the entrance. The wolfman could felt each inch going inside him, in a matter of seconds his ass was full with that cock.

— Aaaaaahhhhh! Ahhahahaha! It’s just that? I knew that you were just bullshitting me with that talk about make me…— Shirou had to shut up. When he stared at Alan’s rod he saw that only half of his member were fully inside.

—Oh. Don’t worry, I didn’t even start. — With a powerful stroke, the young man pushes the rest of his behemoth inside of an unprepared Shirou. The impact was massive, the beastman never had felt something like that in all his centuries.

—AAAAAAAAAAHHHHHHHHHHHHHHHH! — Shirou moaned loudly.

The Sylvasta started to do several strokes at once, each stroke so fast and strong that the sound of his groin colliding with the hip was echoing through the room. Alan started a mixture of laughter and moans while commanding all the action.

— Where is your stubbornness now, huh? Say something! — The pretentious boy said, he was panting, his face blushing, visibly affected. — You are a disappoint to me. I thought that the protector of Anima City would be more of a challenge. Look at you, you little bitch!

Shirou was well aware of everything Alan said, while being fucked, and partially agreed. If he was truly a so-called “Hero” he had to show to that stupid brat his strength. The beastman used his legs to trap Alan in the position he was in, then he used all the energy that left in it to change the situation. He threw the Sylvasta in the floor, now he was the one dictating the action. He still was feeling the huge staff deep inside him, squeezing his insides, that was incredible.

The gray haired man started to move, his ass going up and down, while Alan tried to be in the control again, but it was useless. Despite the youngest not wanting to admit, he was the one enjoying the most. Both were trapped in that wild sexual demonstration of power and none of them would give up. Shirou could felt that his climax was coming, just a little bit more and…

— AAAAAAHHHHHHH! ENOUGH! — Alan would not give away. Suddenly a wave of power came over him and he turn the fight again. Shirou was throw away from the position he had and lay face down on the floor. When the surprised wolfman looked behind he saw that Alan Sylvasta emanated a certain aura, his clothes had turned into rags that covered nothing. He had completely lost his mind and became an animal driven only by desire.

— I don’t understand what is happening, but…Come your beast! —Shirou said.

Alan jumped in the top of the other man, forcing him to lay down in the ground in the perfect position to be fucked. Without waiting any moment, he put his massive cock into Shirou and start to fuck him like a monster. It take a minute or two to Shirou get used to that brutal strokes, however, after that, he decided to be carried away by the sex-beast that possessed Alan. In fact, he even moved his butt in favor of being dominated more.

In one point it as clear that both of them were completely invested and devoted in that intercourse. Alan, with an aggressive movement, pulled away the chains that restrained Shirou, probably to have more freedom, actually would be better to say that he broke the chains with his bare hands.

— HOLY SHIT! How did you do that? You are just a human. — The wolfman was incredulous.

— Let’s go to the final stage! AAAAHHHH. — Alan said that and then hold Shirou by the neck and pulled him close to a passionate kiss. It was so hot, sexy and just felt…correct, beside everything that happened before between the two. They forgot about everything, their past, desires and ambitions, the only thing that mattered at that moment were their bodies being connected as lovers and mates.

— AAAAHHH! ALAN! PLEASE! Fuck me! Breed me! COME, ALAN! — The wolfman managed to say, thanks to a little pause in the kissing. Alan blushed even more with that declaration. He grabbed that horny wolf’ ass with his hands, made him lay down even more and then sent a series of strokes, the deep as he could into that hole.

— Yes! You are mine now! My little bitch, I will fuck you every day! I will make you give birth to my children…AAHHH! FUCK! I don’t care if you are not a pure blood, you are…MINE! — Alan and Shirou couldn’t endure more, their dicks were about to explode, and that were exactly what happened.

— AAAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHH!!! — Shirou and Alan roared like wild beasts. It’s was so loud that the room walls cracked.

With a final and definitive stroke, Alan blow his powerful seed inside Shirou. If Shirou were a female, he would definitely be pregnant after all that hot semen got deep into him, but this fact didn’t stop him from moaning like a bitch in heat, while receiving his prize.

—Yes! Give to me! — He felt the seed of his mate filling his hole and then escaping by his entrance, making a puddle in the floor.

However, that wasn’t the end yet. Alan still had some cum to serve his bitch. He stood up, kneeled near to Shirou’s head with a big smile in his face, then he started to masturbates himself, the heat that emanated from that staff was incredible, the drops of semen that began to fell in Shirou’s chest, the wolfman almost couldn’t believe that, that monster was inside him. Shirou fully open his mouth, as if expecting and desiring the next part.

— Good boy! I don’t know how did you do that roar being just a low-class beastman, but, if that is possible so I expect that throat of yours being capable of take a little more. — Alan said, holding his huge cock. Then he put his rod inside the man’s mouth and start to fucking there, as he fucked his ass before. It only lasted a quick moment, before the Sylvasta give another blow, filling that mouth, making cum go all the way into the throat until it reaches Shirou’s stomach.

The two fell exhausted in the floor. The room smelled as semen and savage intercourse. Shirou despite being free from the chains didn’t try to run away, Alan noticed this and come near to him and hugged him kindly and protectively. From this moment they both were forever together as lovers. Shirou accepted the gest, he closed his eyes, feeling the breath and heartbeats of the blond, and decided to rest. They were mates now, they had a connection and even if it was too soon to say if it was love, they knew that something too powerful was forged that day.

Shirou woke up in the next day. He wasn’t in that room anymore, he woke up in a bed in some kind of guest room, still inside the Sylvasta Laboratory. The Sylvasta brat wasn’t there with him. He could had asked to someone where find Alan, but instead decided to leave the place as quick as possible, his adventure there had ended, for now.

When he got home, he came across with a worried Michiru. She said that called him the whole night and he didn’t answer any calls or viewed any of her messages. Of course, he didn’t tell her the truth, preferring to create some excuse to explain why he couldn’t talk to her yesterday.

After some discussion, the topic change to Michiru’s date with Nazuna, the two had some great time together yesterday, and Shirou was glad to see his friend having a nice bond with the person that she loves. His mind suddenly started to think about Alan and he questioned when would be the next time that they would be together again.

**Author's Note:**

> I hope you had enjoy this one-shot and comment what did you thought while reading. 
> 
> I know that's a lot of grammar mistakes in here, but I'm not fluent in English, so please considerate that and maybe you could give me some advice about writing.
> 
> See you!


End file.
